Abstract 20385: Obese Patients Have Decreased Pump Failure with Cardiac Resynchronization Therapy: Insights from the COMPANION Study
Introduction: Several studies have found that obese patients (pts) are more likely to survive chronic diseases, including heart failure, than pts with normal weight. Known as the obesity paradox, this phenomenon has not been fully explored in pts receiving cardiac resynchronization therapy (CRT). Our goal was to determine if obesity was associated with improved survival using data collected from the COMPANION study and investigate if pump failure (PF) or sudden cardiac (SD) death accounted for this difference.
Methods: COMPANION randomized pts to either optimal pharmacologic therapy (OPT) alone or OPT in combination with CRT with or without defibrillator backup (CRT-D and CRT-P). Pts were stratified into two cohorts: Obese if the body mass index (BMI) was > 30 kg/m2 and Normal for BMI ≤ 30 kg/m2. OPT and CRT were compared within each stratum for all-cause mortality (ACM) as well as sudden death (SD) and pump failure (PF) adjudicated as death in the setting of progressive heart failure deterioration or recurrent hospitalization. Time-to-event data were analyzed with a Cox proportional hazards model adjusted for baseline differences between the two groups.
Results: Of 1516 pts with BMI available, 526 (35%) were classified as Obese. Compared to Normal, Obese pts at baseline were significantly younger, more likely to be taking heart failure medications, and less likely to have ischemic heart disease. The adjusted hazard ratios (HR), 95% confidence intervals, and p-values for each analysis are shown in the table below.
Conclusions: Based on this retrospective analysis of COMPANION, significant risk reduction in pump failure death was observed in obese patients who were randomized to CRT-P. Larger studies with more suitable power are necessary to determine if obese pts are protected from sudden death and what their individual benefit may be with CRT-D. The mechanism behind the enhanced treatment effect of cardiac resynchronization in obese pts requires further investigation.
- © 2010 by American Heart Association, Inc.